This study is designed to determine the feasibility of several assays that may serve as surrogate markers of angiogenesis in healthy volunteers. It will also determine the feasibility and identify the variability of several assays that may serve as surrogate markers of angiogenesis in normal volunteers. The study involves performing a skin biopsy and then examining the biopsy site with a video microscope and a laser Doppler imager. Wounds created by the biopsy will be monitored Monday through Friday for 2 weeks.